Seems like there was a problem with that video. Didn’t want to show using the plugin. I deleted the playlist, created a new one and replaced the video.
You can close this one.
I’m using WordPress 3.5 and I also had the same problem. I read somewhere that adding:
define('CONCATENATE_SCRIPTS', false );
to the wp-config.php file will solve the problem. That fixed my issue.
The line has to be before:
require_once(ABSPATH . 'wp-settings.php');
Mine is after:
‘define(‘WP_DEBUG’, false);’
Hope this help!